Comment re: COVID-19 Infection Rates in Vaccinated and Unvaccinated Inmates: A Retrospective Cohort Study

Comment re Ko et al. (2023) - full text: 

In "COVID-19 Infection Rates in Vaccinated and Unvaccinated Inmates: A Retrospective Cohort Study", Luke Ko and his co-authors examine California state prisons, a "high-density congregate setting" that poses tremendous challenges with managing infectious diseases.

I found the article interesting and gratifying but remain puzzled about the unassertive interpretation of results. The researchers found risk differences of "only" 0.52% overall and a "mere" 0.97% in the 50+ age group, yet fail to emphasize that the difference points in the wrong direction, where inmates with a bivalent booster had significantly higher infection rates than inmates without any COVID-19 vaccine "protection".

In this same context, the authors emphasize the small absolute risk differences. However, considering the corresponding relative metrics, they did actually find a 19% (0.52% / 2.72%) risk increase across all inmates who took the booster, along with a 31% greater risk for boosted 50+ year olds. In the oldest age group, the boosted 65+ year olds had a massive 43% greater infection risk, although this cohort's data were considered unreliable.

The discussion and conclusions contain a number of statements that are not supported by the study design. In particular, I wonder where exactly it was shown that "This study supports the benefits of COVID-19 vaccination at a population level, especially in vulnerable, high-density congregate settings." The study in fact suggests the opposite: that there might be more harm than benefit from the boosters! Another phrase about the efficacy of the "bivalent vaccine ... against severe outcomes" is included despite not being the subject of the authors' work, as they do not even distinguish "infections" from cases of actual illness and did not obtain data on hospitalizations.

Some of this language appears to serve as a vow of compliance with the dominant trajectory in health sciences research these days. Let's keep in mind that science progresses through disruption of prior consensus with "perplexing" results like those of Ko et al. These are important results and I am thankful to the authors and the journal for publishing the article and thereby contributing to post-pandemic recovery through a more nuanced, evidence-based discussion of COVID-19 and the vaccines.